Need Help! Lost and cant find any more options

Hello! I have a 1998 4.0ohv 4wd. Recently I got the p1309 code and also the p0171,p074 bank 1 and 2 lean codes. I proceed to change out the Cam Position Sensor and syncro. I did them both correctly exactly by the book. Made sure to put the engine at top dead center ect. I reset the computer ( left battery unhooked for few hours ) and started her right up. It began to relearn itself but started running rough and sputtery. I maybe thought it could be the
TPS ( throttle position sensor )
MAF ( Mass air flow )
IAC ( idle air control )
and air temp gauge.

I ordered a new MAF and TPS since i found a good deal on amazon. I clean the temp gauge and IAC. After another reset it developed this problem.

from 0mph full throttle no acceleration at all. 0. half throttle was quick and fast and sounded healthy. I proceeded to do some research on the fourms and found a issue could be ground wires and PCM ( power control module ,the ecu/computer ) I checked all my grounds and even took off my coil pack and cleaned the grounds under the coil pack and threw it back on. I even checked the fuel filter and got sprayed right in the ear -_- even though i relived the pressure! Right now its doing another computer reset.

My question to you dear kind folks is this. What the hell could it possibility be!?

ive checked spark plugs, cleaned air filter, checked fuel filter, checked all vacuum lines, brand new MAF,TPS, cleaned IAC and temp gauge. I need help please! Im lost and dont know what to do. thank you all so much!

Are you sure the new MAF &TPS are exact replacements?

The next thing I would try is to put the old TPS back on and see what happens. Then, if necessary, put the old MAF back on and check again.

When troubleshooting a problem like this, only change one thing at a time. If you change several things all at once, you don't know which change fixed the problem or caused the new symptoms. That's commonly called The "shotgun" method of troubleshooting and it can get confusing and costly real fast.

Sent from my SM-G920V using Tapatalk

Oops. Accidentally duplicated my post

P1309 - Misfire Detection Monitor not enabled

The computer uses the Cam sensor to detect misfires, as it compares crank sensor and cam sensor timing.
There are other codes if Cam sensor is bad or failing, like ...........
P0340 Camshaft Position Sensor Circuit Malfunction
P0341 Camshaft Position Sensor Circuit Range/Performance
P0342 Camshaft Position Sensor Circuit Low Input
P0343 Camshaft Position Sensor Circuit High Input
P0344 Camshaft Position Sensor Circuit Intermittent

So the codes a computer DOES NOT USE are as important as the one it does use

Sensors rarely fail, they are often replaced, but rarely fail, lol, but don't feel too bad Pro Mechanics replace sensors all the time on speculation, customer is paying for it so who cares
Point is, do NOT replace sensors because of a code or wishful thinking, waste of time and money
I have a 1994 Ranger 4.0l with 400k and every original engine sensor in place, I did change the O2s as they use a chemical reaction and do wear out after 125k or so.

The Cam Synchro needs to be installed with #1 at TDC but not just with crank pulley at TDC, since this is a 4-stroke engine #1 is at Top Dead Center TWO times during 1 full cycle, and you need to time the Cam Synchro to the right TDC, compression stroke TDC.
Pull #1 spark plug out, put compression gauge in #1 and rotate engine by hand until gauge starts to show pressure, as pressure goes up TDC will come around, thats the TDC mark you want.
Or pull out #1 spark plug and put crank on TDC, rotate crank engine "backwards" 1/2 turn, then put finger in spark plug hole and rotate crank forward to TDC again, if your finger gets push out then thats the right TDC, if not rotate crank one full turn back to TDC and thats the right TDC

p0171 - System too Lean (Bank 1)
p0174 - System too Lean (Bank 2)

Bank 1 is passenger side , Bank 2 drivers side
When you get two Lean codes on a V6 engine(or V8) it is almost always an upper intake vacuum leak.

To test if you have a vacuum leak
Warm up engine, drive it for at least 5 minutes
Leave it idling and open the hood
Locate IAC Valve
Unplug it's 2 wire connector

IAC valve will close all the way and engine RPMs should drop to 500, or engine may even stall, either is GOOD, it means no vacuum leak
If idle does NOT drop then there IS a vacuum leak


Lean code means computer is having to open the fuel injectors longer that it calculated, it doesn't mean engine is actually running Lean
O2 sensor on each Bank reports Lean burn, computer opens injectors on that bank longer to get "good" burn, if % of open time gets too high computer sets Lean code for that bank

There are a few reasons for Lean codes, most common is vacuum leak(90% of the time at least), there is more air coming in than computer used in its calculations, so it has to open injectors longer to compensate for the extra air.
MAF(mass air flow) sensor tells computer how much air is coming in(a leak by passes this sensor), check air tube from MAF to intake, a leak there is the same as vacuum leak
MAF sensors get dirty, they can be cleaned with a no-residue electronics cleaner, this should be done every 2 years, some do it once a year.

Fuel pressure, computer doesn't have a fuel pressure sensor, it was programed in 1998 to expect 65psi fuel pressure at each injector.
If your fuel filter gets dirty or fuel pump is starting to fail, then fuel pressure at the injectors drops, so............
Computer has to open the injectors longer to get same amount of fuel out at 35 psi than it would at 65psi, and that would also cause Lean code

Thank you Ron! I will go ahead and go one by one and check! To get the engine at Top Dead Center for the syncro, I took apart the intake manifold, took off the cam sensor, went down under and used a socket wrench to turn the crank with the car in neutral until the ford cam position tool fit on top of the syncro. Once it fit i knew it was at tps required to do postion sensor. I then installed the new syncro with the tool as well.

Im sure they are good replacments. Got them off amazon oem, i will put the original tps to test it, but i know for a fact the MAF was bad, I would unplug it and no change happened to engine idel ect

Ill run it tomorrow and see if its still stuck in ( limp mode ) ill check grounds , and see if it gives me any codes,

Im sure they are good replacments.

Click to expand...

Cool. Not trying to pick on you. But I have seen bad parts come from new packages. In fact, I ordered a compression tubing fitting the other day and the part that arrived was a totally wrong part but it was sealed in a package bearing the correct part number.

P1309 - Misfire Detection Monitor not enabled

This doesn't mean Cam sensor is not working

Computer would use P0340 Camshaft Position Sensor Circuit Malfunction if it wasn't working

It means the Computer doesn't understand or can't compare Crank sensor and Cam sensor data
1998 was the last year the 4.0l Ranger used the 3 wire Cam sensor
1999 got the 2 wire cam sensor
These are not interchangeable, not a wiring difference, they are different types of sensors
So you need to replace with 3 wire Cam sensor

If crank sensor was an issue then engine would not start, crank(CKP) sensor is the only sensor that can cause a no start.
So we will assume the P1309 is a Cam sensor timing issue but..........you retimed it, and while it needs to be timed it isn't that precises, computer has some leeway to adjust Cam timing pulse

Just to confirm you put Cylinder #1(passenger side front) on Compression stroke TDC, right?
There are TWO TDCs, right one and wrong one

P1309 will come back after reset even with everything correct, it can take a few drive cycles for it to clear itself.
So not an instant fix, give it a few days

Couple of simple things
Clean BOTH battery terminals/cables
Look down by crank pulley passenger side, you will see the Crank sensor, have a look at the wiring on it, make sure back of pulley is not caked with mud or other debris

1998 Ranger will have the Computer wiring plugin at top of firewall center passenger side, so easy to get at
But also easy for water to get inside
Looks like this: http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/1e/53/c8/medium/0900c152801e53c8.gif
Unhook the battery, good time to clean terminals
Remove the bolt that holds the Computer connector in place and pull off the 104 wire connector
Have a look inside at computer side and connector side, look for any corrosion
Reinstall connector, this will make sure wires are making good contact

Simply unplugging and plugging back in ANY wiring connector can clean the contacts inside, so always try that first before replacing anything
This is often why "new" sensors fix problems, lol, old sensor was fine just unplugging connector and plugging it back in would have fixed it, which was done when installing the "new" sensor

RonD said:

P1309 - Misfire Detection Monitor not enabled

This doesn't mean Cam sensor is not working

Computer would use P0340 Camshaft Position Sensor Circuit Malfunction if it wasn't working

It means the Computer doesn't understand or can't compare Crank sensor and Cam sensor data
1998 was the last year the 4.0l Ranger used the 3 wire Cam sensor
1999 got the 2 wire cam sensor
These are not interchangeable, not a wiring difference, they are different types of sensors
So you need to replace with 3 wire Cam sensor

If crank sensor was an issue then engine would not start, crank(CKP) sensor is the only sensor that can cause a no start.
So we will assume the P1309 is a Cam sensor timing issue but..........you retimed it, and while it needs to be timed it isn't that precises, computer has some leeway to adjust Cam timing pulse

Just to confirm you put Cylinder #1(passenger side front) on Compression stroke TDC, right?
There are TWO TDCs, right one and wrong one

P1309 will come back after reset even with everything correct, it can take a few drive cycles for it to clear itself.
So not an instant fix, give it a few days

Couple of simple things
Clean BOTH battery terminals/cables
Look down by crank pulley passenger side, you will see the Crank sensor, have a look at the wiring on it, make sure back of pulley is not caked with mud or other debris

1998 Ranger will have the Computer wiring plugin at top of firewall center passenger side, so easy to get at
But also easy for water to get inside
Looks like this: http://repairguide.autozone.com/znetrgs/repair_guide_content/en_us/images/0900c152/80/1e/53/c8/medium/0900c152801e53c8.gif
Unhook the battery, good time to clean terminals
Remove the bolt that holds the Computer connector in place and pull off the 104 wire connector
Have a look inside at computer side and connector side, look for any corrosion
Reinstall connector, this will make sure wires are making good contact

Simply unplugging and plugging back in ANY wiring connector can clean the contacts inside, so always try that first before replacing anything
This is often why "new" sensors fix problems, lol, old sensor was fine just unplugging connector and plugging it back in would have fixed it, which was done when installing the "new" sensor

Click to expand...

--- Reply ---

Thank you for the info! the sensor came with the new syncro , so might as well install it. I followed this exactly, http://www.explorerforum.com/forums/index.php?threads/easy-camshaft-synchronizer-replacement.368598/

Im about to go run and test the truck to see whats going on, Its been disconnected from battery over night, has brand new MAF,TPS,CAM syncro and sensor, cleaned IAC and temp gauge lets see if the 4.0 gives me any problems. I also checked all my gounds,cleaned terminals, even took off the coil pack and sanded down the ground there with wire brush and rubbing alcohol to get grime off. Ill also check the pulley and computer connection! Ill try to take a video with problems if I run into any. Thank you so much for the help everyone and especially Ron, Its very frustrating when you think you found the issue and it ends up not being in, then you do it again and again till your only option left is to take your exhaust off to check clogged cats or something. Really do appreciate the help!

That link tells you to, basically, mark the old synchro's position and then re-install new synchro in the same position.
But you were getting code P1309....................which means old one was in the WRONG position, possibly

So no, that wouldn't be the right way to do it
If you were replacing a squealing synchro, worn out bushings, then yes that would be fine
But that's not what you needed to do, you need to make sure new one is in correct position

Which means you need to put engine at #1 TDC Compression stroke and then install new synchro

Back from test drive

Just got back from test drive, let it run in the driveway for a few minutes then went for a drive. Ran around for 5 minutes normal without flooring it or anything. I then went half throttle , accelerates smooth,clean healthy sounding a little slower then expected but i am on 33s and 410 so didnt expect it do be quick. did a 0 to 30/45ish half throttle and took video did fine. Did 0- ? full throttle wont even budge! Starts mis firing,back firing, popping, low low rpm's about to die. Has 0 power. Anything full throttle under 30mph does this, any speed more then 30 full wide open has power.Moves quick no sputtering. Occasionally when i stop and put it in park or neutral i rev it, and itll sometimes start random mis firing, sputtering ect, but then itll go back to normal and rev fine. I got a video of this happening as well. Any idea on what this issue could be!? Ive changed all the sensors correctly, cleaned the pcm memory, cleaned all connections, checked battery connections as well. Could it be a bad coil pack? Or maybe cats?

RonD said:

That link tells you to, basically, mark the old synchro's position and then re-install new synchro in the same position.
But you were getting code P1309....................which means old one was in the WRONG position, possibly

So no, that wouldn't be the right way to do it
If you were replacing a squealing synchro, worn out bushings, then yes that would be fine
But that's not what you needed to do, you need to make sure new one is in correct position

Which means you need to put engine at #1 TDC Compression stroke and then install new synchro

Click to expand...

Ohhhh, okay, ill redo it this week and do #1 TDC correctly and reinstall the syncro that way. I also checked all the fuses they are fine, and did little checks elsewhere.

Also no check engine lights, but! When i scanned for codes i got a p0171 system too lean bank 1. and only that code.

It will take awhile but you will probably get 0174 as well

Did you do the IAC Valve vacuum leak test?